Systems for labeling products in the production process are well known. Generally, such labeling systems utilize a conveyor which transports vertically placed products through the system. As the products approach the labeler, a low limit control device detects and meters the presence of the product to determine whether enough product is present to allow passage into the labeler. As the products enter the labeler, synchronized infeed timing screws position, space, and meter the products on the conveyor for subsequent labeling.
An overhead stabilizer assumes control of the product as it leaves the infeed timing screws. This stabilizer functions to hold the product securely against the conveyor as the product passes through the labeler.
The product passes two electronic sensor devices as it approaches the applicator heads. A product sensor is responsible for detecting the presence of the product and subsequently initiating dispensing of a label. A label sensor is responsible for detecting the movement of the label and web during dispensing and signaling a brake to stop dispensing.
A pressure sensitive label is applied to the product or substrate using an applicator head system. A web of label material is unwound from the supply roll, guided across an idler roll and down an apron plate to the peeler plate. The peeler plate guides the web to the peeler tip. The peeler tip peels the label from the web as it is pulled around the tip toward a pressure roller/knurled roller assembly. These applicator heads are operated by a motorized indexing system.
A tension wiper holds the label flat as it passes under the label sensor. The label wiper provides the initial touch of the label to the product, is mounted to the peeler plate and extends past the tip in order to wipe the leading edge of the label to the product as it passes the peeler tip.
The pressure roller/knurled roller assembly is responsible for pulling the label web from the supply roll to the peeler tip, as well as pulling the used web liner from the tip to the rewind roll. A rewind roll serves to take up the used web material. Finally, the labeled product is passed through a label wiper roller system which contacts the label and ensures that the label is securely affixed to the product.
The prior art devices and methods of labeling have several problems and disadvantages. Frequently, the label applied to the product is wrinkled or contains bubbles between the product and the label. Additionally, the label wiper rollers in some instances scratch the label. These imperfections yield undesirable results, and render the product unfit for its intended use, thereby resulting in product waste.
Prior art labeling machines require the peeler plates to actually contact the product. In the prior art methods the product is pushed past the applicator in such a way that the motion of the product moves the peeler around the product. The peeler arm and label wiper are biased or urged into actual contact with the product panel. Oftentimes, the initial contact of the product into the peeler arm causes an exaggerated movement of the peeler arm away from the product as the label dispensing begins, resulting in the aforementioned wrinkling and bubbling. To achieve this contact, the overhead stabilizer must apply a substantial amount of pressure to the product so that the product does not move during this process. The pressure from the overhead stabilizer can cause distortion of the product shape in this situation, which may then result in distortion of the applied label.
Before development of the present invention, labeling machines were not capable of effectively and practically labeling a concave panel surface. Additionally, such labeling machines are limited in the materials which can be used in the labels while still achieving acceptable appearance.
The present invention addresses all of the above problems and disadvantages by providing a peeler plate which, because it is cam driven, comes in close proximity to the product when applying the label, without actually contacting the product. This allows the smooth application of the label to the product without using the motion of the product itself to achieve this result. Therefore, fewer wrinkles and bubbles occur during labeling and less pressure is applied to the product by the overhead stabilizer. The present invention also eliminates the need for a label wiper roller assembly. Individual cams are developed to mirror the contour of specific products thereby enabling the device to apply labels to a variety of contoured panel surfaces.